Container packages or cartons of the single-use disposable type are largely employed today to pack consumer goods such as, for example, beverages like milk or juice. The container package is usually made from packaging material in the form of a laminate with carrier layers of paperboard or cardboard, and different layers of thermoplastic laminated thereto. The laminate may also have a different core material, such as metal foil. The packaging material, which is often in the form of a web or sheet blank, is folded, sealed and finally formed into a liquid-tight container package.
The finished container package will preferably include an opening arrangement that is simple to open and pour from, which pours the liquid contents in a compact jet and without any risk of spilling or dripping. However, container packages manufactured from a packaging material consisting of a paper laminate may be difficult to tear open and fold to form a functional pouring spout. Moreover, when the intention is to reclose and reseal such container packages, it is not possible to make the package liquid-tight once again.
It is also known in the art to manufacture container packages having a main portion formed from a packaging laminate as described above but having an upper defining surface formed from an injection molded thermoplastic lid. The thermoplastic lid also includes an opening arrangement integral with the lid. This opening arrangement is relatively easy to open but is not liquid-tight on reclosure and resealing.
In order to obviate the above-outlined drawbacks, various forms of penetrating screw stoppers or plugs have been produced which are placed on the surface of the container package so that the screw plug penetrates through the surface layer when the package is opened.
It is further known in the art to form a partly integrated pouring spout from the surface of the packaging material. The pouring spout is surrounded by a sealing portion of the so-called screw stopper or plug type which, on being opened, tears off an outer portion of the pouring spout. That part of the pouring spout which is torn off during the opening operation has been sealed against the outer sealing portion by means of heat. As a result, the tear-off operation generally results in the pouring spout having a rough outer edge, which may render pouring of the contents enclosed in the container package difficult.
Not all of the prior art types of screw stopper opening are provided with an arrangement which prevents the unauthorized opening of the container package. Today, consumers greatly appreciate an opening arrangement in which it may immediately be seen that no unauthorized person has been able to open the container package and tamper with its contents. It is, therefore, desirably that a screw stopper or plug also include an arrangement which prevents the unauthorized opening of the container package.